It has been estimated that of the approximately $30 billion spent each year in the United States for medical tests, as much as 60% of that amount ($18 billion) is wasted on unnecessary tests; i.e., those which, for a given patient, would not be needed if the physician had the benefit of a reliable medical history. See, for example, Are We Hooked on Tests, U.S. News & World Report, Nov. 23, 1987, pp. 60-65, 68-70, 72.
This problem of unnecessary testing is particularly acute in cases where a patient is about to undergo surgery and, in order to determine the proper anesthesia, the patient's general medical history is taken.
This medical history strongly influences which diagnostic tests the medical staff chooses to perform before surgery. For example, if the patient discloses that he or she has any pain or discomfort upon urination, or has noticed any blood in the urine, then a urinalysis (a chemical analysis of the urine) ought to be performed. But if those symptoms are not present, it is considered medically unnecessary to administer a urinalysis, absent some other medical indication for the test.
Under current medical practice, it requires about seventy-five or more questions to determine which, if any, of the various available pre-operative tests (urinalysis, chest x-rays, EKG, etc.) might have to be performed before determining what anesthesia ought to be used during surgery. If the physician is not sure that all these questions were properly asked, or has doubts about the care with which the patient's answers have been recorded, he or she is likely to include in the battery of pre-operative tests many that could have been excluded based on an accurate patient history.
To save the time of physicians, questionnaires have been devised that can be administered by a nurse or other trained medical worker, or even directly filled in by the patient. But the time of a trained medical worker is also too valuable to spend on such tasks, since that makes the individual unavailable to perform other, more pressing, medical tasks which require such training.
If the patient completes the questionnaire alone, he or she may overlook or ignore some of the questions. Also, if the patient usually reads in a foreign language or has vision problems, he or she may have trouble completing the questionnaire alone.
Even if a questionnaire is fully and properly filled out, tallying of the patient's answers to determine which tests are needed is a time-consuming and tedious task, in the course of which medical workers sometimes inadvertently introduce errors.
Because of these problems, all too often a reliable medical history of this type is not taken prior to surgery, in which case the patient may have to undergo a comprehensive battery of pre-operative tests, many of them unneeded. These unnecessary tests are expensive for the patient and a burden on an already overworked medical system. In addition, the more tests are done the greater is the risk of false positives and iatrogenic harm from pursuit of false positives. Therefore, there is a great need to "automate" the reliable taking and tabulating of pre-operative test questionnaires.